Reactions observed in boys of various ages (ten to fourteen) to a crippling, progressive, and fatal illness (muscular dystrophy)

Intelligence and the gene for Duchenne muscular dystrophy.

“…Several papers have reported the mean per- formance IQ higher than the mean verbal IQ (Sherwin and McCully, 1961;Zellweger and Niedermeyer, 1965;Zellweger and Hanson, 1967), but the present study shows no significant difference. Neither does it show that a significantly greater proportion of patients score higher on the performance subtests than on the verbal subtests; the performance IQ was higher than the verbal in 22 cases, while the verbal was higher in 17 cases.…”

“…5). Sherwin and McCully (1961) found little evidence that children, including the brightest ones, tended to compensate for motor deficiency by concentration on verbal activities and interest, but such compensation is suggested by the significant increase in verbal IQ with increasing age shown in this study.…”

“…Some researchers have found the incidence of mental retardation among dystrophics to be the same as that among the general population (Bell, 1943;Walton and Nattrass, 1954; Schoelly and Fraser, 1955;Sherwin and McCully, 1961;Gamstorp and Smith, 1964), while others explain the slightly lower intelligence scores found in their studies on the basis of environmental consequences of chronic disease, and/or socio-economic status (Morrow and Cohen, 1954;Truitt, 1955). There is now, however, a substantial body of evidence showing decreased mental functioning in DMD patients (Zellweger, 1946;Becker, 1953;Giannini and Marcheschi, 1959;Walton, 1963).…”

Evidence for early impairment of verbal intelligence in Duchenne muscular dystrophy

“…The majority of boys in these two studies were relatively unimpaired in their motor functioning, with only a small number of them in wheelchairs. In studying dystrophic children confined to wheelchairs, Sherwin and McCully (1961) anticipated greatly lowered performance IQ scores but found very little discrepancy between the verbal and performance IQ scores. 4 of the boys, despite considerable motor impairment, obtained higher performance IQs than verbal IQs.…”

“…In most studies two and even three different intelligence tests have been administered in order to cover the range of ages in the samples (Allen and Rodgin, 1960;Kozicka, Prot, and Wasilewski, 1971;Prosser et al, 1969;Sherwin and McCully, 1961;Zellweger and Hanson, 1967;and Zellweger and Niedermeyer, 1965). Contrary to the assumption followed by those researchers that intelligence tests such as the WISC, the Wechsler Adult Intelligence Scale (WAIS, Wechsler, 1955), and the Stanford-Binet Intelligence Scale (S-B, Terman and Merrill, 1937) are comparable in estimating IQ means and can be used interchangeably, Hannon and Kicklighter (1970) reported that the WAIS produces a significantly higher IQ score of approximately 7 IQ points over the WISC for 15to 16-year-olds in the less-thanaverage intelligence range.…”